Cultures of ligament fibroblasts in fibrin matrix gel.

The cellular properties of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) fibroblasts have been analyzed in a three-dimensional fibrin matrix gel (FMG) system. The MCL fibroblasts proliferated significantly faster than ACL fibroblasts in 10% fetal bovine serum (FBS). FMG contraction resembles soft-tissue wound contraction. Transforming growth factor-beta1 (TGF-beta1) (5 ng/ml) caused a significantly faster rate of FMG contraction than control (0.5% FBS) in both ACL and MCL fibroblasts. Unlike the cells in 10% FBS, this faster rate of FMG contraction was achieved without increasing the initial cell number. In the FMG, the MCL fibroblasts demonstrated significantly higher collagen synthesis per cell than ACL fibroblasts between the days 2 and 6 of culture. These differences in cellular properties of the ACL and MCL fibroblasts that were observed in vitro may explain the differences in the healing potential of these ligaments in vivo.